Conventional door architecture for automobiles provides a movable door, typically pivotally mounted to the frame of the automobile for movement between a closed position latched against the frame of the automobile and an opened position in which the door is pivoted away from the frame to allow access and egress to the passenger compartment of the automobile. These conventional automotive doors carry a latch mechanism that engages a corresponding striker on the adjacent frame member of the automobile to secure the door in the closed position. The latch mechanism is operably coupled with a locking mechanism that fixes the latch mechanism in an engaged position to prevent the door from opening. The latch mechanism is typically mechanically connected to outside and inside door handles that when manipulated cause the latch mechanism to release from the latch keeper unless the lock mechanism is engaged. The lock mechanism can be released either mechanically or via an electronic signal that causes the lock mechanism to move to a position that allows the latch mechanism to release from the striker.
A passive entry system for an automotive vehicle would be defined as a system that will open the door of the vehicle without requiring conventional input from the operator, such as pulling on the outside door handle to affect a mechanical release of the latch mechanism or such as physically manipulating the lock mechanism, either mechanically or by requiring the operator to push a button on a key fob to send an electronic signal, to unlock the latch mechanism. A passive entry system is different from a passive unlock system for an automobile, which are known in the art as is indicated below, in that the passive unlock system simply causes the lock mechanism to unlock without requiring specific input from the operator, although the operator needs to provide a physical input to cause the door to open.
In U.S. Pat. No. 6,290,269, granted to Jamie Bodley-Scott, et al on Sep. 18, 2001, a passive vehicle door locking system is disclosed in which an integrated latch mechanism can receive mechanical inputs from the interior door handle and the exterior door handle. The electronic controller receives signals from a remote device, such as the key or the key fob, and is operated from the exterior of the vehicle. If the battery in the driver's key or key fob transmitter becomes discharged, the key or key fob could be provided with a passive transponder which can be energized, and can cooperate with a coil antenna provided at a known location in the door. The coil antenna will not be permanently energized, but will be energized for a predetermined period of time following a release movement of the exterior door handle. Thus, the driver will hold his key or key fob in the known proximity of the coil antenna to release the lock mechanism to allow the mechanical operation of the door handle.
Another passive unlock system is found in U.S. Pat. No. 6,801,134, granted to David Juzswik on Oct. 5, 2004, wherein the system includes an automatic-unlock transceiver/control operatively connected to a lock mechanism to control the operation thereof through use of an interrogation signal and a response signal. An identification transceiver carried by the operator may be in the form of a key fob. The portable transceiver receives the interrogation signal and responds with a response signal to gain access into the vehicle. The response signal conveys an appropriate security code to identify the portable transceiver. In response to the reception of response signal, the control provides a signal to the lock mechanism for actuation thereof. Thus, the authorized person can gain entry into interior of vehicle without manually operating any unlock device. The control utilizes an initiation stimulus that is indicative of the authorized person being in close proximity to vehicle and desiring entrance into the vehicle. A sensor is provided in conjunction with the door handle and is operatively connected to the control such that when hand of the authorized person reaches to actuate the handle, the interrogation sequence is initiated.
Similarly, in U.S. Pat. No. 6,825,752, issued on Nov. 30, 2004, to Pratik Nahata, et al, the control unit detects an intention of an operator to actuate the lock mechanism, such as an electronic solenoid lock, and transmits a challenge signal to determine whether the operator is authorized to operate the vehicle. An electronic key device, such as a key fob or electronic badge within the vicinity of the challenge signal, responds to the challenge signal through a transponder and transmits a key code to control unit. If the key code matches a security code stored by the control unit, an actuator may unlock the vehicle. The control unit may determine whether the port is already open by a position sensor and the control unit may also seek to determine whether operator has moved the latch, such as via a door handle, to further indicate the operator's intention to enter the vehicle. If the door is closed and the latch has been moved, the control unit may actuate the lock mechanism. An electronic apparatus operable to recognize a key fob and distinguish whether the key fob is located internally of the vehicle or externally is taught in U.S. Pat. No. 7,046,119, granted on May 16, 2006, to Riad Ghabra, et al.
A patent application by Riad Ghabra, et al, published as U.S. Patent Publication No. 2006/0114100 on Jun. 1, 2006, and related patent applications by Riad Ghabra No. 2006/0255906 on Nov. 16, 2006, and by Carl Gilbert, et al, published as U.S. Patent Publication No. 2006/0255908 on Nov. 16, 2006, teach a remote keyless vehicle unlock system that includes a portable communication device having a plurality of actuation buttons disposed on a face of the portable communication device. The portable communication device, such as a remote keyless entry (RKE) fob, broadcasts RF signals to a vehicle base communication module located within the vehicle for actuating vehicle entry functions such as unlocking and locking the vehicle door. The passive unlock system allows a user to unlock a vehicle without an actuation of a pushbutton on portable communication device 32 or other portable device. The system may be a polling or non-polling system. In a polling system, the communication module broadcasts a challenge signal at timed intervals for determining the presence of an authorized portable communication device when the vehicle doors are locked and the passive entry system is active. The portable communication device broadcasts a response RF signal to a vehicle based communication module for remotely actuating a respective vehicle entry function such as unlocking or locking vehicle door. Alternatively, a wake signal may be used in a polling system for waking the portable communication device prior to broadcasting the challenge signal. In a non-polling system, the vehicle based communication module waits for a triggering event, such as the actuation of vehicle door handle, before broadcasting the challenge signal to portable communication device.
A remote keyless entry system is disclosed in U.S. Patent Publication No. 2007/0040649 by James Dulgerian, et al, published on Feb. 22, 2007, in which a key fob acts as portable controller and has control buttons which instruct the vehicle via RF transmission to lock door and unlock doors. A door handle pull or other input may alert the door control module. When the portable controller is close enough to receive the signal, the controller responds with an encrypted RF signal that may include a module identifier. After receiving, decrypting, and validating the message, the system sends a command to unlock the door. The system can determine whether the portable controller is located internally or externally of the vehicle. The door controller may also receive input from wakeup switch, which may be connected to the door handle to provide a signal that the operator has lifted the door handle to gain access to the vehicle.
None of these prior art systems provide a true passive entry operation, as defined above. Accordingly, it would be desirable to provide a passive entry system that would recognize the operator and provide an apparatus that would be operable to unlock and open the vehicle door without requiring any active input from the operator, including the manipulation of the vehicle door handle, except to touch the vehicle to indicate the desire to open the respective door.